The Wegener-Bergeron-Findeisen process – Its discovery and vital importance for weather and climate

Limitations of the Wegener–Bergeron–Findeisen Mechanism in the Evolution of Mixed-Phase Clouds

Phase transformation and precipitation formation in mixed-phase clouds are usually associated with the Wegener–Bergeron–Findeisen (WBF) process in which ice crystals grow at the expense of liquid droplets. The evolution of mixed-phase clouds, however, is closely related to local thermodynamical conditions, and the WBF process is just one of three possible scenarios. The other two scenarios invo...

Representation of Arctic Mixed-Phase Clouds and the Wegener-Bergeron- Findeisen Process in Climate Models: Perspectives from a Cloud-Resolving Study

Simulations of Arctic mixed-phase clouds in forecasts with CAM3 and AM2 for M-PACE

[1] Simulations of mixed-phase clouds in forecasts with the NCAR Atmosphere Model version 3 (CAM3) and the GFDL Atmospheric Model version 2 (AM2) for the MixedPhase Arctic Cloud Experiment (M-PACE) are performed using analysis data from numerical weather prediction centers. CAM3 significantly underestimates the observed boundary layer mixed-phase cloud fraction and cannot realistically simulate...

Modeling of the Wegener–Bergeron– Findeisen process—implications for aerosol indirect effects

A new parameterization of the Wegener–Bergeron–Findeisen (WBF) process has been developed, and implemented in the general circulation model CAM-Oslo. The new parameterization scheme has important implications for the process of phase transition in mixed-phase clouds. The new treatment of the WBF process replaces a previous formulation, in which the onset of the WBF effect depended on a threshol...

Evaluation of Mixed-Phase Cloud Parametrizations in Short-Range Weather Forecasts with CAM3 and AM2 for Mixed-Phase Arctic Cloud Experiment

Mixed-phase clouds dominate low-level Arctic clouds in cold seasons and have a significant impact on the surface energy budget. However, the treatment of mixed-phase clouds in most current climate models is crude because the detailed microphysical processes involved in mixed-phase clouds are not completely understood, primarily owe to the paucity of cloud observations in the past. Improving mix...